DESCRIPTION (provided by applicant: Diabetes is a disease of multiple organs responding to complex genetic and environmental factors. A complete understanding of insulin resistance and type 2 diabetes mellitus (T2DM) requires an integrative approach that asks how different cell types influence each other through hormonal, neural, and metabolic signals all in the context of extra-organismal stresses including overnutrition and disruptions in normal circadian rhythms. A goal of all studies proposed in this application is to explain normal and pathological metabolism in molecular terms, emphasizing both cell autonomous processes as well as those that depend on organismal integration. The Program Project brings together five outstanding investigators, each with considerable past success as an independent investigator, but each also with a genuine belief in the value of scientific collaboration. Each PI focuses on a specific organ system and how it interacts with other tissues and external stresses, and works in close communication other PIs who study related problems. In Project 1, Lazar addresses how resistin coordinates the multi-organ response to nutritional overload, in which an inflammatory response leads to adverse consequences in insulin target tissues and the cardiovascular system. In Project 2, Stoffers focuses on the response of the beta cell to the stress of peripheral insulin resistance, testing an intriguing model that connects transcriptional regulation to endoplasmic reticulum biosynthesis and cell growth. In Project 3, Ahima uses a mouse feeding entrainment model that mimics circadian disruption in humans to examine how the central nervous system influences hepatic metabolism. In Project 4, Kaestner also studies the response to a perturbed central clock, but in the context of how the hormonal milieu influences the transcriptional control of liver glucose metabolism. Lastly, in Project 5, Birnbaum also considers how hepatic metabolism responds to the stress of obesity, but also asks how it is normalized by the antidiabetic drug metformin. The projects are supported by three Cores that provide histochemical analysis, generation of genetically modified mice, and their metabolic phenotyping. PUBLIC HEALTH RELEVANCE: The proposed studies will address major and specific questions relevant to diabetes and metabolic diseases. At the same time, the specific investigators, environment, and format of this proposal facilitate interactions that should enhance the discovery process. There is an excellent likelihood that advances made by this program project group will have a positive impact on the epidemics of diabetes and metabolic diseases that are ravaging our society.